Structural basis of geriatric voiding dysfunction .6. Validation and update of diagnostic criteria in 71 detrusor biopsies

Purpose: Refined criteria of distinctive patterns of detrusor ultrastructure in geriatric voiding dysfunctions have been developed as standard protocols for pathological evaluation of detrusor biopsies. This study was performed to test completeness and routine applicability of these protocols, corroborate our original ultrastructural/urodynamic correlations in larger material and identify subtle correlations that may have been elusive in our original study of 35 cases. Materials and Methods: A total of 71 endoscopic detrusor biopsies was obtained from 44 elderly subjects grouped following comprehensive clinical and urodynamic evaluation into those with normal aging bladder, detrusor overactivity, impaired detrusor contractility, bladder outlet obstruction or a combination. Biopsies were evaluated ultrastructurally and randomly, and blinded to clinical information. Using standard protocols the primary ultrastructural pattern(s) was identified, additional auxiliary features were recorded and pathological diagnoses were made. Biopsies were grouped accordingly, still blindly, and correlated with urodynamic groups determined independently prior to biopsy. Results: Our observations confirmed that the standard protocols are complete and readily applicable to routine ultrastructural evaluation of detrusor biopsies. They corroborated our previously reported ultrastructural/urodynamic matching of the biopsies in every case and revealed new constant features of the normally aging detrusor. We identified ultrastructural correlates distinguishing moderate and severe from mild or borderline (but not moderate from severe) impairment of detrusor contractility. Conclusions: The proposed protocols are consistently applicable to the routine pathological diagnosis of geriatric voiding dysfunction in detrusor biopsies. A diagnostic algorithm was developed to serve as a practical guide for making such diagnoses, and gaining insights into the pathophysiology of geriatric and possibly other voiding dysfunctions.